Trying to replicate the bar problem from Triesch 2007, "Synergies Between Intrinsic and Synaptic PlasticityMechanisms".
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Main implementation in replicate_barprob_triesch2007IPandSP.m.
Currently could not replicate bar detection. Either SP alone, or SP+IP (tried a few learning rates between 1E-4 to 1E-1) would result in a roughly normal weight vector distribution, not a bimodal distribution like the paper. Also tried playing around with target rate mu = 0.01, 0.05, 0.1, bar probability p_bar = 1/N, 1/2N and initial activation parameters a_init, b_init - did not matter.
Possible issues might arise from:
- Implementation of IP or Hebbian SP
- How inputs are generated, whether the way to normalize is correct
- How weights are initialized. Currently, drawn from a uniform distribution [0, 1], then normalized to unit length. Additionally, also tried a normal distribution, a log-normal distribution and a few beta distributions (didn't work).